Do you recommend weekly SQ immunoglobulin replacement for an asplenic patient who only responded to 4/23 pneumococcal serotypes after the Prevnar 20 vaccine?

Immunoglobulin replacement therapy is indicated for those with evidence humoral immune dysfunction. This is typically evaluated in a T cell independent fashion using a pneumovax as a challenge mechanism (or possibly Salmonella typhi vaccine which is also polysaccharide). Poor response to prevnar is concerning but is a T cell dependent evaluation, so does not confirm humoral immune dysfunction. In this scenario, I would evaluate with a polysaccharide vaccination and if they still have poor S pneu...

If the patient has recurrent/chronic infections (check her sinuses as well, to help rule out other forms of pneumonitis), and other diagnoses such as CF have been ruled out, then her diagnosis may be specific (polysaccharide) antibody deficiency and IgG augmentation might be necessary. Given her relatively high IgG level, it is important to determine if she has a major subclass deficiency and to be sure she does not have any kind of paraprotein or polyclonal B-cell activation (i.e., SLE or EBV)....

Yes!